1. Field of the Invention
The invention relates to a vehicle with loading boxes receiving loads, at least one of the loading boxes being capable of being raised and lowered in the vertical direction by lifting devices, the lifting devices being arranged and the middle frame running in the longitudinal direction of the vehicle, and the loading boxes being capable of being unloaded, level with the ground, in a lower position.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
A generic vehicle with a body is described in EP 07 33 003 B1. Here, however, it is not possible to load both loading boxes, without the vehicle having to be turned around on the loading ramp.
U.S. Pat. No. 3,666,130 describes a similar vehicle. It is likewise not possible, here, for loads to be loaded from one side of the vehicle to the other side.
A vehicle, in which two loading boxes can be lowered from a driving position into a ground-level position for unloading via hydraulic/pneumatic cylinders, is also described in FR 2 504 465. The mechanism, here, is arranged in the region above the middle frame, in a comparable way to the two publications mentioned above, in such a way that, here too, it is not possible for loads, to be loaded through, since the space above the middle frame is occupied by the mechanism and by reinforcing elements.
DE 94 08 263 U1 describes a vehicle, in which loading boxes can be lowered into a ground-level position for unloading by means of lifting devices arranged on the middle frame. In this case, the complete body is connected to the loading boxes and is moved together with these. Here too, in a disadvantageous way, it is not possible for loads to be loaded through, since the loading boxes are fixed in the driving position via bracing cones; and it is not possible for the loading boxes to be raised beyond this driving position. Another disadvantage is that, in the region of the rear axle, part of the loading surface above the middle frame is rigidly formed. Due to the roof structure moved together with the loading boxes, this loading surface can be utilized only over a very small part of its height, since there is otherwise a collision between the roof, the vehicle and the load supported there.
EP 0 818 351A, DE 298 07 108 U1 and U.S. Pat. No. 4,708,572 A in each case describe bodies, in which parts of the loading surface of the vehicle are brought partially laterally next to the vehicle via lever mechanisms or the like and at the same time or thereafter are lowered. As a result of this lateral movement taking place additionally to the lowering, in a disadvantageous way, on the one hand, the activating elements become very complicated and therefore susceptible to faults and heavy and, on the other hand, the lateral space requirement necessary for unloading the articles from the vehicle is very high.
As regards the further general prior art, reference may also be made to JP 58 180328 A which shows a loading surface, part of which can be lowered via a kind of scissor structure. Here, however, as a consequence of the design, no lowering to the ground can take place, so that it becomes only slightly easier for the vehicle to be unloaded.
The object on which the invention is based is to provide a vehicle, in which the loading boxes can be raised and lowered, while at the same time it should be possible for the loads to be loaded through from one side of the vehicle to the other, and it is also possible to transport loads which extend transversely over. the entire width of the vehicle.
This object is achieved, according to the invention, in that at least one of the loading boxes can be brought into at least three positions by the lifting devices, the lifting devices being arranged on the loading boxes, as seen in the longitudinal direction of the vehicle, in such a way that the largest part of the space above the middle frame is available as a further loading surface, in an upper position bottoms of the loading boxes being located at the same height as the further loading surface, a normal driving position of the vehicle being between the upper and the lower position, and the vehicle also being capable of being driven in the upper position.
The arrangement according to the invention of the lifting devices makes it possible to install a further rigid loading surface on the middle frame of the vehicle and thus make it possible to load from the right side of the vehicle to the left side over this loading surface.
It is advantageous, in this case, that the loading boxes can be brought into at least three positions by the lifting devices and, in a lower position, the loading boxes are capable of being unloaded level with the ground, the normal driving position of the vehicle being between the upper and the lower position, and the vehicle also being capable of being driven in the upper position. In addition to the advantages already known from the generic vehicle, this affords the advantage that, since the vehicle is also capable of being driven in the upper position of the loading boxes, bulky loads which cover both loading boxes and the further loading surface lying above the middle frame can be transported.
In the upper position, the bottoms of the loading boxes are at the same height as the further loading surface, this corresponding at the same time to the ramp height in a particularly advantageous refinement. By the ramp height is meant, here, that height which, in the case of loading ramps for vehicles, in particular heavy goods vehicles, is generally customary for loading them.
In an advantageous refinement of the invention, there may be provision for the lifting devices to be arranged at the edge or at the front and/or rear end region of the loading boxes on the middle frame.
This constitutes an even more advantageous arrangement of the lifting devices, without these being capable of causing an obstruction when loads are being loaded through.
In a further advantageous development, there may be provision for the lifting devices each to have at least one transverse yoke which runs transversely to the longitudinal direction of the vehicle, bottoms of the loading boxes being connected to the transverse yoke by means of tie rods.
By means of the suspension of the loading boxes on the transverse yoke, the loading boxes can be raised and lowered in a highly advantageous way. At the same time, the loading surface has no disturbing obstacles apart from the tie rods and the lifting devices.
Advantageously, there may be provision, furthermore, for the loading boxes to have laterally and, if appropriate, also at the rear, on the outside of the vehicle, tailboards which can be fixed in at least one position pointing upward approximately perpendicularly to the bottom of the loading box and one position pointing approximately perpendicularly downward.
It is thereby advantageously possible to fold the tailboards downward and fasten them there when the vehicle is driven with loaded loads, the loading boxes being in the upper position. The downwardly folded tailboards then serve as drive-under protection, so that a passenger car, in the event of an accidental collision with the vehicle according to the invention, cannot penetrate under the structure of the vehicle body.